1. Field of the Invention
The present invention relates to utility carts of the two-wheeled, hand-operated variety frequently employed for moving refrigerators, ranges, washers and similar appliances as well as large cumbersome containers and the like, and more particularly to improvements in such carts facilitating their use in moving loads along staircases.
2. Description of the Prior Art
The use of two-wheeled utility carts also frequently referred to as hand or warehouse trucks is rather common. The trucks typically include an elongated frame with handles near an upper end thereof and a pair of wheels near the bottom thereof and with a pair of generally orthogonal load bearing surfaces including a lower lip or platform which may be slid under a heavy object to be moved whereupon the object and truck are pivoted about the wheels so as to balance the load on the wheels allowing a single individual to move an otherwise unmanageable load. So long as the truck remains on a relatively level surface, heavy loads can easily be moved, however, when the load is to be moved up or down a staircase, a load which was rather easily maneuvered by a single person frequently requires two or three people to prevent the load from getting out of control.
The prior art is replete with attachments and modifications for such trucks attempting to adapt them to stairway use bearing eloquent testimony to the problems associated with the movement of heavy loads up or down a staircase, but unfortunately leaving the problem substantially unsolved. These attachments and the modifications have frequently taken the form of staircase engaging skids, rollers or roller supported tracks, however, in these cases the truck user must at all times exert sufficient force to prevent the truck and load from sliding down the staircase in an uncontrolled manner. Also, in the use of such trucks on staircases, at least one of the two or more persons moving the heavy load must be positioned on a higher step than the step or steps on which the load and truck rest and must, therefore, bend over, reaching perhaps lower than his own feet to grasp the truck, exerting an upward force thereon. In such a position, the user is precariously exposed to back injuries and the like and is further exerting forces on the truck and load at an unfavorable angle.